Vacuum evaporation deposition is a process in which substances to be deposited are heated in vacuum environment to evaporate or sublimate, to condensate or deposit on a surface of a low-temperature workpiece or substrate, so that a film is formed. After being heated, substances to be deposited evaporate or sublimate in an evaporation crucible, and are emitted through an evaporation hole over the evaporation crucible. While a substrate to be deposited passes an outlet of the evaporation hole at a constant speed, the evaporated substances are gradually cooled and the rate of evaporation is also gradually reduced after leaving the evaporation crucible, and finally a film is formed on the surface of the substrate to be deposited.
According to the number and the arrangement mode of evaporation holes, the evaporation source of the evaporation apparatus may be divided into a point evaporation source, a linear evaporation source and a planar evaporation source. As for the point evaporation source, there is only one evaporation hole over the evaporation crucible and the deposition area is one relatively small range which is centered at the evaporation hole. The point evaporation source is usually used for depositing a film with a relatively small size. As for the linear evaporation source, there are a plurality of evaporation holes which are arranged linearly over the evaporation crucible. When the substrate to be deposited is stationary, the area of the deposited film on the substrate to be deposited formed by the linear evaporation source has a shape of a straight line. As for the planar evaporation source, there are a plurality of evaporation holes which are arranged on a whole surface over the evaporation crucible, such that the area of the deposited film is a whole area corresponding to the evaporation holes arranged on the whole surface.
In addition, according to the setting angle of the evaporation hole over the evaporation crucible, the evaporation hole may be divided into a vertical evaporation hole and a tilted evaporation hole. Especially when multiple materials are applied for depositing a doped film, it is required to adjust a tilting direction of evaporation holes of evaporation crucibles for multiple materials, so that evaporation holes over evaporation crucibles of different materials are oriented to a same positon on the substrate to be deposited.